The ruling issued just hours after the court heard oral arguments is a major victory for Republicans, who pushed for the major increases in contribution limits in the past legislative session despite warnings from Democrats that they would run afoul of state law protecting voter-approved laws.

The court said it will issue a formal opinion explaining its reasoning later.

The court overturned an October decision by the Arizona Court of Appeals that found the law conflicted with the Voter Protection Act. That law requires a three-fourths vote of the Legislature to make major changes to voter-approved laws. The brief court order also lifted the injunction the appeals court put in place blocking the higher limits from taking effect.

The Arizona Citizens Clean Elections Commission wanted the limits blocked, arguing the 1998 law creating the state's public campaign financing system set clear limits on donations. The law creating the commission reduced the limits at the time by 20 percent and only allowed for increases tied to inflation.

The five justices focused on that argument. They questioned whether the Citizens Clean Elections Act could be interpreted to allow for a 20 percent reduction from higher limits adopted by the Legislature.

"We simply come back to whether the voters in 1998 intended to adopt the limits as then existed ... or intended to adopt a function saying the limits will be 80 percent of what the Legislature otherwise sets them to be," Justice Scott Bales said while questioning Joseph Kanefield, who represented the commission.

That's the position taken by lawyers representing Senate President Andy Biggs and House Speaker Andy Tobin, who argued there was no proof voters intended to bar the Legislature from raising the limits without a supermajority.

"If the voters had intended to set firm limits, they would have put those numbers in the Act," lead attorney Michael Liburdi told the justices.

Liburdi wasn't immediately available to comment after the ruling was released late Tuesday afternoon.

Democrats argued that sharply raising the limits would just allow a flood of special-interest cash into political campaigns.

Biggs said the Legislature raised the limits for the opposite reason.

"I think the theory of the legislation that passed was that you have all this dark money out there that basically controls everybody's campaigns, and it is because Arizona has one of the lowest, if not the lowest limits in the nations," he said after the ruling was released. "And that allowed outside interests to influence campaigns."

Louis Hoffman, who chairs the Clean Elections Commission and authored the original law, said he was deeply disappointed by the ruling.

"I'm disappointed they didn't recognize what the voter intent of this was and what the plain language was," Hoffman said. "I think they've cut breaks for other initiatives, even where there's been plain drafting errors, and I thought this kind of ambiguity was one that they would otherwise follow."

"I also wish they had taken the case this summer when we asked them to rather than putting us through the lower courts, seemingly needlessly," he added.

Voters passed Proposition 200 in 1998 after a decade that saw a rash of political corruption cases, including the indictments of several lawmakers caught taking payoffs, the impeachment of Gov. Evan Mecham in 1988, and the 1997 resignation of Gov. Fife Symington after a felony conviction. The idea was to provide public funding for candidates that choose to use it, thereby cutting the influence of special interests.

Under the new limits, candidates for statewide and legislative office would be allowed to raise thousands of dollars more each election. For example, the measure increased the limit for legislative candidates from $488 through the primary and general elections to nearly $2,500 from individual donors and $5,000 from some political committees. The law also allows candidates to collect the maximum contribution twice -- during the primary and the general election.

Republicans said the change was necessary to address unconstitutionally low campaign limits and fight against political groups increasingly using independent funds to influence elections. The U.S. Supreme Court's decision in the Citizens United case in 2010 lifted many restrictions on corporate spending in political elections and paved the way for a flood of campaign cash from corporations, unions and wealthy interests.

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